Generally speaking, a virtual keyboard is as wide as a touch screen. If the touch screen/virtual keyboard is too wide and a large number of keys are arranged on the same row, an operator cannot touch or control the keys with both thumbs (the left/right thumb cannot touch or control the keys at the middle of the virtual keyboard). In view of the problem that the touch screen/virtual keyboard is too wide and the operator cannot control the keys for inputting with both thumbs, the existing technical solution is to split the virtual keyboard and the keys thereon into two independent keyboards (i.e. half of keyboard on the left and half of the keyboard on the right) and display the two keyboards on the left and right sides of the touch screen. Although this can satisfy the requirement of the operator of controlling the keys with both thumbs, negative issues caused by splitting the keyboard apparently exist. For example, two keyboards are required for input, and the man-machine interface is poor. Also, the change of the original key layout and the relative positions of the keys would affect the operability of the keyboard.